code: def validate_document(doc) -> bool:
      """Check an individual document."""
      # Example checks
      if not isinstance(doc, Document):
          return False
  
      if not doc.page_content:
          return False
  
      return True
  
file_path: mindsdb/mindsdb/integrations/handlers/rag_handler/ingest.py
imports: import time
  from typing import List
  import pandas
  from langchain.schema import Document
  from langchain.text_splitter import RecursiveCharacterTextSplitter
  from langchain.vectorstores import VectorStore
  from mindsdb.integrations.handlers.rag_handler.settings import PersistedVectorStoreSaver, PersistedVectorStoreSaverConfig, RAGBaseParameters, VectorStoreFactory, df_to_documents, get_chroma_client, load_embeddings_model, url_to_documents
  from mindsdb.utilities import log
label_desc: Use image node_id 1 for calling a global function with example usage: validate_document(doc) and returns: True, False, False